Ladder leveling device



\NVENTOR THOMAS J. BROWN DEAN LAURENCE ATTORNEY Sept; 8, 1970 T. J.BROWN LADDER LEVELING DEVICE Filed March 17, 1969 United States PatentOflice 3,527,321 Patented Sept. 8, 1970 3,527,321 LADDER LEVELING DEVICEThomas J. Brown, Rte. 3, Ridge Road, Box 114, Yazoo City, Miss. 39194Filed Mar. 17, 1969, Ser. No. 807,518 Int. Cl. E06c 7/44 U.S. Cl.182-205 4 Claims ABSTRACT OF THE DISCLOSURE A device which allowsladders to be quickly leveled and firmly placed on uneven ground. Thedevice has a ratchet mechanism contained in a telescoping sleeveattached to the bottom of the ladder rail. A spring attached to theouter sleeve allows for the automatic extension and positioning of theleg and easy shorting of the leg.

BACKGROUND OF THE INVENTION The present invention relates to a ladderleveling device. More particularly it relates to a device which allowsfor the leveling of a ladder standing on an uneven base by extending oneor more of the ladder rails.

Painters and other workmen who use ladders in their trade often have toerect the ladders on an uneven surface such as hillsides, stairs, ramps,and such. Many methods have been devised for dealing with the problemincluding wedging rocks or blocks under the short leg, which isdangerous, and various forms of ladder rail extenders.

Many of the extender devices of the prior art such as Bratt 1,718,891and Kimes 2,350,116 use a knurled knob, wedge or claw to directly engagethe ladder rail. These systems suffer from two serious deficiencies;they depend on frictional engagement to maintain the adjustment and thedevice makes direct and destructive contact with the material of theladder rail resulting in a chewing up of the rail and a shortened usefullife for the ladder.

The prior art has also used a ratchet type device.

Curran in U.S. Pat. 970,425 shows a ratchet device wherein t-wo toothedracks must be manually engaged and disengaged. This device would bedifficult to adjust because it necessitates manually engaging anddisengaging the teeth of the ratchet while supporting the ladder.

De Stefano in U.S. Pat. 2,517,771 discloses another device whichnecessitates the manual disengagement of the ratchet before adjustmentcan be made in either direction.

SUMMARY OF THE INVENTION It is the general object of the invention toavoid and overcome the foregoing and other difficulties and objectionsto prior art devices by providing a safe, simple, inexpensive and easilyoperable leveling device.

Another object of the invention is to provide a ladder with a levelingdevice which will attach to and adjust the length of one or more ladderside rails.

A further object is to provide a device which will protect and notdamage the ladder side rails.

Still a further object is to provide a leveling device for a ladderwhich automatically provides a positive lock when extended.

Another object of the invention is to provide a ladder extending devicewhich can be extended by the force derived from the foot of theoperator.

An additional object of the invention is to provide a ladder levelingdevice constructed with the minimum number of operating components.

The aforesaid objects of the invention and other objects will becomeapparent on reading the description. These objects are achieved byproviding a device attached to the base of a ladder rail which as innerand outer telescoping members. The inner member or sleeve is attached tothe lower end of a ladder rail by any means known in the art such asnails, screws, crimp, rivets, etc. Most preferably the inner sleevewould be screwed on to a wooden ladder rail and riveted or welded to ametal ladder rail.

The inner sleeve covers and protects the four faces of the ladder rail.On one face of the inner sleeve is a ratchet rack. This ratchet rack maybe integrally formed on the surface of the inner sleeve or permanentlyattached thereto by welding, bolting or any other such means known tothe art. Preferably the ratchet rack is welded to the face of the innersleeve which faces toward the ground when the ladder is in place. Theteeth of the ratchet rack are inclined downwardly and outwardly so theflat surface of a tooth of the rack is toward the base of the ladder.

The inner sleeve is made of metal. Preferably the sleeve is made of astrong resistant metal which will provide strong structural support forth ratchet of the device. Most preferably the sleeve and ratchet rackare made of steel.

The outer member or sleeve is slidably mounted over said inner sleeve.The outer sleeve completely covers the inner sleeve when the device isin the retracted position. The outer sleeve is provided with a footeither integrally formed thereon or attached to the outer sleeve toimprove the foundation and support afforded the ladder. The foot can beof a type ordinarily available for attachment to ladder rails and may bepermanently or temporarily attached.

On an inner face of the outer sleeve there is provided a tension meansso positioned that it will act as a pawl in conjunction with a ratcheton the inner sleeve allowing for the adjustment of the leveling device.

Preferably the pawl is a flat spring which extends upward and outwardfrom the inner face of the outer sleeve at an angle substantiallysimilar to the inclination of the teeth of the ratchet. The tensionforce in the pawl is directed away from the face of the outer sleeve towhich the pawl is attached. The pawl is attached to the outer sleeve bymeans well known in the art. Most preferably the pawl is welded to theouter sleeve. The pawl is a fiat spring made of any material commonlyused to provide a resilient structurally strong spring, preferably thepawl is made of metal and most preferably of steel.

Attached to said pawl is a disengagement means for removing the pawlfrom contact with a tooth of the ratchet and thereby allowing theretraction of the outer sleeve. An opening is provided in the outersleeve to allow access to the retraction means. Preferably theretraction means is a projection permanently attached to said pawl, andmost preferably the retraction means is a knob attached to a post weldedto the fiat spring pawl.

The outer sleeve is made of metal. Preferably the sleeve is made of astrong resistant metal most preferably the outer sleeve is made ofsteel.

Both the inner and outer sleeve may be made more resistant to weatheringand also be made self lubricating by coating and bonding to the surfacesthereof a plastic material such as polyethylene or polyfuronatedhydrocarbons such as Teflon by means known in the art.

The flat spring pawl of the device provides sufficient tension againstthe inner sleeve to frictionally maintain the outer sleeve of theleveling device in engagement with the inner sleeve of the device so theladder may be moved about without the outer sleeve falling off, yet whenthe ladder is being positioned a very slight pressure by the operator onthe outer sleeve will extend the outer sleeve to the desired length andthe flat spring pawl will automatically and positively engage theratchet therefore pro viding a firm and steady ladder base.

3 BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a side elevation view of astepladder, on a level surface, having the leveling device secured ateach side rail thereof.

FIG. 2 is a front elevation view of a ladder, on an uneven surface,having the leveling device secured to each rail thereof.

FIG. 3 is a' sectional view of the apparatus.

FIG. 4 is a horizontal sectional view of the device taken along line 4-4of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings,wherein like reference characters designate like or corresponding partsthroughout the several views, there is shown a ladder having verticallyextending side rails 11 interconnected by laterally spaced horizontalrungs 12. A ladder leveling device 13 is positioned on the lower portionof the side rail 11.

In the retracted position as seen in FIG. 1, all that is visible of theleveling device 13 is an outer sleeve 20 with a shaft 24 terminating ina knob 25 protruding therefrom.

'In FIG. 2 the device is shown in an extended position with the innersleeve 30 emerging from the outer sleeve 20 as it is lowered tocompensate for the sloping land.

As shown in FIG. 4 the ladder leveling device 13 has an outer sleeve 20terminating in a foot 27. A channel 21 is provided in the outer sleeve20 to slidably receive inner sleeve 30 including the ratchet rack 31.The outer sleeve 20 has a flat spring 22 afiixed to it in a channel 23provided therefor. The tension in the flat spring 22 forces the springinto engagement with a tooth 32 of the ratchet rack 31 therebypreventing the downward movement of the inner sleeve 30. As can be seenin FIGS. 2 and 4 the inner sleeve 30 is afiixed to the rail 11! ofladder 10.

Again referring to FIGS. 3 and 4 a shaft 24 projecting through opening26 in outer sleeve 20, and terminating in knob 25 is provided fordisengaging flat spring 22 from tooth 32, and retracting spring 22 intogroove 23 to allow inner sleeve 30 to telescope along channel 21 intoouter sleeve 20.

Although the device is shown on a stepladder it will work equally aswell on a pole ladder and the device is not limited by the material fromwhich the ladder is made.

It should be understood that the foregoing disclosure relates to only apreferred embodiment of the invention and modifications and changes maybe made in the shape, size and material without departing from thespirit and scope of the invention as claimed.

What I claim is:

1. A ladder leveling device in combination with ladder rails whichcomprises an inner and outer member, said inner member being attached tothe base of said ladder rails and having on one face thereof a ratchetrack, said outer member being slidably mounted over said inner memberand having an opening positioned in one face of said outer member; atension means positioned on the interior side of said face of said outermember containing said opening wherein: the tension force in saidtension means is directed away from said outer member toward said innermember for positivelyengaging the toothed rack of said inner member,disengagement means affixed to said tension means and passing throughsaid opening in said outer member for disengaging said tension meansfrom said rack.

2. A device according to claim 1 wherein said tension means is a flatspringpawl.

3. A device according to claim 1 wherein said outer member is arectangular sleeve having an opening positioned in one face of saidsleeve, a tension pawl attached to said inner faceof said outer sleeve,said pawl under a tension force directed away from the face of saidouter sleeve to which said pawl is attached, disengagement means affixedto said pawl and passing through said opening.

4. A device according to claim 3 wherein said inner member is arectangular sleeve having a ratchet rack afiixed thereto with the teethof said rack inclined downwardly and outwardly and said pawl affixed tosaid outer sleeve is a flat spring which extends upwardly at an anglesubstantially similar to the inclination of the teeth of said ratchetrack.

- References Cited UNITED STATES PATENTS 898,973 9/1908 Curran 182205REINALDO P. MACHADO, Primary Examiner

